import React,{Component} from "react";export default class CreateRef extends Component {    //专人专用    myRef = React.createRef()    myRef2 = React.createRef()    render() {        return (            <div>                <input ref={this.myRef} type="text" placeholder='点击按钮提示数据'/>                <button onClick={this.click}>点我提示左侧的数据</button>                <input onBlur={this.blur} ref={this.myRef2} type="text" placeholder='失去焦点提示数据'/>            </div>        )    }    click = () =>{        alert(this.myRef.current.value)    };    blur = ()=>{        alert(this.myRef2.current.value)    }}